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Fencer Intel
high 7.5

CVE-2020-1920 json

Regular expression denial of service in react-native

published 2021-06-01 5 y ago modified 2026-06-17 4 mo ago also GHSA-7f53-fmmv-mfjv , EUVD-2021-1447

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

Summary

A regular expression denial of service (ReDoS) vulnerability in the validateBaseUrl function can cause the application to use excessive resources, become unresponsive, or crash. This was introduced in react-native version 0.59.0 and fixed in version 0.64.1.

Patch / fix

  • npm react-native 0.62.3, 0.64.1
  • facebook react-native 0.64.1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-1920 updated cvss 7.5

react-native: Regular expression denial of service in validateBaseUrl function

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.36% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
npm react-native
>=0.59.0, <0.62.3
>=0.63.0, <0.64.1
0.62.3
0.64.1

Affected products

  • Facebook react-native

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity
  • CWE-697 Incorrect Comparison
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.